The present invention relates generally to the fluid flow meters and, more particularly, to a local wall heat flux/temperature meter for convective fluid flow and method for utilizing the same.
Since the design requirements, goals, and objectives of plasma-facing components (PFCs) and electronic heat sinks (EHSs) are evolving, the development of an experimental conjugate multi-dimensional, flow boiling database may provide the basis for computational fluid dynamic (CFD) comparisons, flow boiling correlation modifications, and adaptations that include single-side heating effects for detail PFC and EHS flow channel and substrate design studies, which may lead to cost-effective and robust designs. Many papers have been published reporting either new or modified flow boiling correlations. Generally, there appears to be good confidence in predicting water flow boiling for uniformly heated circular channels with or without twisted tapes. However, most all PFCs and EHSs involve single-side heated flow channels and, hence, depend on at least two-dimensional, and in some cases three-dimensional, conjugate data and analysis for new or modified flow boiling or single-phase correlations with two- and possibly three-dimensional influences.
Conjugate heat transfer modeling has proven useful in forming baselines and identifying important parameters affecting peaking factors and data reduction for the spectrum of high heat fluxes found in a wide variety of applications. For various applications requiring different fluids, the results show the following: (1) the coexistence of three flow boiling regimes inside the single-side heated flow channel, (2) the correlational dependence of the inside wall heat flux and temperature (fluid independent), and (3) inaccuracies that could arise in some data reduction procedures (fluid independent). However, for PFC applications in fusion reactors, work to expand conjugate heat transfer analyses from simple circular and complex geometries to PFC geometries is still needed for consistently predicting peaking factors and prototypic conditions.
According to one embodiment of the invention, a method includes providing a conduit having a fluid flowing therethrough, disposing a plurality of temperature measurement devices inside a wall of the conduit, positioning at least some of the temperature measurement devices proximate an inside surface of the wall of the conduit, positioning at least some of the temperature measurement devices at different radial positions at the same circumferential location within the wall, measuring a plurality of temperatures of the wall with respective ones of the temperature measurement devices to obtain a three-dimensional temperature topology of the wall, determining the temperature dependent thermal conductivity of the conduit, and determining a multi-dimensional thermal characteristic of the inside surface of the wall of the conduit based on extrapolation of the three-dimensional temperature topology and the temperature dependent thermal conductivity.
Embodiments of the invention provide a number of technical advantages. Embodiments of the invention may include all, some, or none of these advantages. In one embodiment, a local wall heat flux/temperature meter allows measurement of 2-D wall-fluid interface thermal phenomena (heat flux, temperature and heat transfer coefficient) never before measured independent of fluid. The meter may assist in developing new and improved designs, may be independent of fluid flowing in channel, may assist in assessing sophisticated software (Computational Fluid Dynamic, CFD) used to numerically predict turbulent and multiphase fluid flows, and may be used in many industries (nuclear reactor and power generation, electronic cooling, medical, aircraft, spacecraft, chemical, petroleum, material processing, HVAC, non-destructive testing, CFD-user Industries, Automobile, safety, etc.), to monitor safety concerns that are directly related to the inside wall heat flux or temperature.
Other technical advantages are readily apparent to one skilled in the art from the following figures, descriptions, and claims.